A symptom of this the underlying problem will be the following message from the Cisco server in the DialOut/EZ trace log: "This command has no effect on this line; use modem AT commands instead".
After that message, modem initialization will stop.
This behavior has only been reported for Cisco 36xx models.
This message was introduced in IOS 12.2(5.5), which incorrectly outputs it on the console port (or on a reverse telnet session.) This is bug fixed via in IOS 12.2(9.3)T. You need to upgrade to 12.2(9.3)T or above (Cisco recommends 12.2(10a)) or downgrade to release 12.2(5d).
1st of September, 2009